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We conduct a comprehensive study on dropout galaxy candidates at z ∼ 9–16 using the first 90 arcmin2 James Webb Space Telescope (JWST) Near Infrared Camera images taken by the early release observations (ERO) and early release science programs. With the JWST simulation images, we find that a number of foreground interlopers are selected with a weak photo-z determination (Δχ 2 > 4). We thus carefully apply a secure photo-z selection criterion (Δχ 2 > 9) and conventional color criteria with confirmations of the ERO Near Infrared Spectrograph spectroscopic redshifts, and obtain a total of 23 dropout galaxies at z ∼ 9–16, including two candidates at zphot=16.25−0.46+0.24 and 16.41−0.55+0.66 . We perform thorough comparisons of dropout galaxies found in our work with recent JWST studies, and conclude that our galaxy sample is reliable enough for statistical analyses. We derive the UV luminosity functions at z ∼ 9–16, and confirm that our UV luminosity functions at z ∼ 9 and 12 agree with those determined by other Hubble Space Telescope and JWST studies. The cosmic star formation rate (SFR) density decreases from z ∼ 9 to 12, and perhaps to 16, but the densities at z ∼ 12–16 are higher than the constant star formation efficiency model. Interestingly, there are six bright galaxy candidates at z ∼ 10–16 with M UV < −19.5 mag and M * ∼ 108−9 M ⊙. Because a majority (∼80%) of these galaxies show no signatures of active galactic nuclei in their morphologies, the high cosmic SFR densities and the existence of these UV-luminous galaxies are explained by the lack of suppression of star formation by the UV background radiation at the pre-reionization epoch and/or an efficient UV radiation production by a top-heavy initial mass function with Population III–like star formation.

We present the evolution of the mass–metallicity (MZ) relation at z = 4–10 derived with 135 galaxies identified in JWST/NIRSpec data taken from the three major public spectroscopy programs of ERO, GLASS, and CEERS. Because there are many discrepancies between the flux measurements reported by the early ERO studies, we first establish our NIRSpec data reduction procedure for reliable emission-line flux measurements and errors, successfully explaining Balmer decrements with no statistical tensions thorough comparisons with the early ERO studies. Applying the reduction procedure to the 135 galaxies, we obtain emission-line fluxes for physical property measurements. We confirm that 10 out of the 135 galaxies with [O iii] λ4363 lines have electron temperatures of ≃(1.1–2.3) × 104 K, similar to lower-z star-forming galaxies, which can be explained by heating by young massive stars. We derive the metallicities of the 10 galaxies by a direct method and the rest of the galaxies with strong lines using the metallicity calibrations of Nakajima et al. applicable for these low-mass metal-poor galaxies, anchoring the metallicities with the direct-method measurements. We thus obtain the MZ relation and star formation rate (SFR)–MZ relation over z = 4–10. We find that there is a small evolution of the MZ relation from z ∼ 2–3 to z = 4–10, while interestingly the SFR–MZ relation shows no evolution up to z ∼ 8 but a significant decrease at z > 8 beyond the errors This SFR–MZ relation decrease at z > 8 may suggest a break of the metallicity equilibrium state via star formation, inflow, and outflow, while further statistical and local-baseline studies are needed for a conclusion.

We characterize the earliest galaxy population in the JADES Origins Field, the deepest imaging field observed with JWST. We make use of ancillary Hubble Space Telescope optical images (five filters spanning 0.4–0.9 μm) and novel JWST images with 14 filters spanning 0.8−5 μm, including seven medium-band filters, and reaching total exposure times of up to 46 hr per filter. We combine all our data at >2.3 μm to construct an ultradeep image, reaching as deep as ≈31.4 AB mag in the stack and 30.3–31.0 AB mag (5σ, r = 0.″1 circular aperture) in individual filters. We measure photometric redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts z = 11.5−15. These objects show compact half-light radii of R 1/2 ∼ 50−200 pc, stellar masses of M ⋆ ∼ 107−108 M ☉, and star formation rates ∼ 0.1−1 M ☉ yr−1. Our search finds no candidates at 15 < z < 20, placing upper limits at these redshifts. We develop a forward-modeling approach to infer the properties of the evolving luminosity function without binning in redshift or luminosity that marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the impact of nondetections. We find a z = 12 luminosity function in good agreement with prior results, and that the luminosity function normalization and UV luminosity density decline by a factor of ∼2.5 from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical models for evolution of the dark matter halo mass function.

We present JWST NIRCam nine-band near-infrared imaging of the luminous z = 10.6 galaxy GN-z11 from the JWST Advanced Deep Extragalactic Survey of the GOODS-N field. We find a spectral energy distribution (SED) entirely consistent with the expected form of a high-redshift galaxy: a clear blue continuum from 1.5 to 4 μm with a complete dropout in F115W. The core of GN-z11 is extremely compact in JWST imaging. We analyze the image with a two-component model, using a point source and a Sérsic profile that fits to a half-light radius of 200 pc and an index n = 0.9. We find a low-surface-brightness haze about 0.″4 to the northeast of the galaxy, which is most likely a foreground object but might be a more extended component of GN-z11. At a spectroscopic redshift of 10.60 (Bunker et al. 2023), the comparison of the NIRCam F410M and F444W images spans the Balmer jump. From population-synthesis modeling, here assuming no light from an active galactic nucleus, we reproduce the SED of GN-z11, finding a stellar mass of ∼109 M ⊙, a star formation rate of ∼20 M ⊙ yr−1, and a young stellar age of ∼20 Myr. Since massive galaxies at high redshift are likely to be highly clustered, we search for faint neighbors of GN-z11, finding nine galaxies out to ∼5 comoving Mpc transverse with photometric redshifts consistent with z = 10.6, and a tenth more tentative dropout only 3″ away. This is consistent with GN-z11 being hosted by a massive dark-matter halo (≈8 × 1010 M ⊙), though lower halo masses cannot be ruled out.

We report the discovery of 15 exceptionally luminous 10 ≲ z ≲ 14 candidate galaxies discovered in the first 0.28 deg2 of JWST/NIRCam imaging from the COSMOS-Web survey. These sources span rest-frame UV magnitudes of −20.5 > M UV > −22, and thus constitute the most intrinsically luminous z ≳ 10 candidates identified by JWST to date. Selected via NIRCam imaging, deep ground-based observations corroborate their detection and help significantly constrain their photometric redshifts. We analyze their spectral energy distributions using multiple open-source codes and evaluate the probability of low-redshift solutions; we conclude that 12/15 (80%) are likely genuine z ≳ 10 sources and 3/15 (20%) likely low-redshift contaminants. Three of our z ∼ 12 candidates push the limits of early stellar mass assembly: they have estimated stellar masses ∼ 5 × 109 M ⊙, implying an effective stellar baryon fraction of ϵ ⋆ ∼ 0.2−0.5, where ϵ ⋆ ≡ M ⋆/(f b M halo). The assembly of such stellar reservoirs is made possible due to rapid, burst-driven star formation on timescales < 100 Myr where the star formation rate may far outpace the growth of the underlying dark matter halos. This is supported by the similar volume densities inferred for M ⋆ ∼ 1010 M ⊙ galaxies relative to M ⋆ ∼ 109 M ⊙—both about 10−6 Mpc−3—implying they live in halos of comparable mass. At such high redshifts, the duty cycle for starbursts would be of order unity, which could cause the observed change in the shape of the UV luminosity function from a double power law to a Schechter function at z ≈ 8. Spectroscopic redshift confirmation and ensuing constraints of their masses will be critical to understand how, and if, such early massive galaxies push the limits of galaxy formation in the Lambda cold dark matter paradigm.

We present the ultraviolet luminosity function and an estimate of the cosmic star formation rate density at 8 < z < 13 derived from deep NIRCam observations taken in parallel with the MIRI Deep Survey of the Hubble Ultra Deep Field (HUDF), NIRCam covering the parallel field 2. Our deep (40 hr) NIRCam observations reach an F277W magnitude of 30.8 (5σ), more than 2 mag deeper than JWST public data sets already analyzed to find high-redshift galaxies. We select a sample of 44 z > 8 galaxy candidates based on their dropout nature in the F115W and/or F150W filters, a high probability for their photometric redshifts, estimated with three different codes, being at z > 8, good fits based on χ 2 calculations, and predominant solutions compared to z < 8 alternatives. We find mild evolution in the luminosity function from z ∼ 13 to z ∼ 8, i.e., only a small increase in the average number density of ∼0.2 dex, while the faint-end slope and absolute magnitude of the knee remain approximately constant, with values α = − 2.2 ± 0.1, and M * = − 20.8 ± 0.2 mag. Comparing our results with the predictions of state-of-the-art galaxy evolution models, we find two main results: (1) a slower increase with time in the cosmic star formation rate density compared to a steeper rise predicted by models; (2) nearly a factor of 10 higher star formation activity concentrated in scales around 2 kpc in galaxies with stellar masses ∼108 M ⊙ during the first 350 Myr of the universe, z ∼ 12, with models matching better the luminosity density observational estimations ∼150 Myr later, by z ∼ 9.

We present electron densities n e in the interstellar medium (ISM) of star-forming galaxies at z = 4–9 observed by the JWST/NIRSpec GLASS, Early Release Observations, and CEERS programs. We carefully evaluate the line-spread functions of the NIRSpec instrument as a function of wavelength with the calibration data of a planetary nebula taken on board, and obtain secure [O ii] λ λ3726, 3729 doublet fluxes for 14 galaxies at z = 4.02–8.68 falling on the star formation main sequence with the NIRSpec high- and medium-resolution spectra. We thus derive the electron densities of singly ionized oxygen nebulae with the standard n e indicator of the [O ii] doublet, and find that the electron densities of the z = 4–9 galaxies are n e ≳ 300 cm−3 significantly higher than those of low-z galaxies at a given stellar mass, star formation rate (SFR), and specific SFR. Interestingly, the typical electron densities of the singly ionized nebulae increase from z = 0 to z = 1−3 and z = 4–9, which is approximated by the evolutionary relation of n e ∝ (1 + z) p with p ∼ 1–2. Although it is not obvious that the ISM property of n e is influenced by global galaxy properties, these results may suggest that the nebula densities of high-z galaxies are generally high due to the compact morphologies of high-z galaxies evolving by re∝∼(1+z)−1 (r vir ∝ (1 + z)−1) for a given stellar (halo) mass whose inverse square corresponds to the p ∼ 2 evolutionary relation. The p ∼ 1−2 evolutionary relation can be explained by a combination of the compact morphology and the reduction of n e due to the high electron temperature of high-z metal-poor nebulae.

We present a new derivation of the Milky Way’s current star formation rate (SFR) based on the data of the Herschel InfraRed Galactic Plane Survey (Hi-GAL). We estimate the distribution of the SFR across the Galactic plane from the star-forming clumps identified in the Hi-GAL survey and calculate the total SFR from the sum of their contributions. The estimate of the global SFR amounts to 2.0 ± 0.7 M ⊙ yr−1, of which 1.7 ± 0.6 M ⊙ yr−1 coming from clumps with reliable heliocentric distance assignment. This value is in general agreement with estimates found in the literature of last decades. The profile of SFR density averaged in Galactocentric rings is found to be qualitatively similar to others previously computed, with a peak corresponding to the Central Molecular Zone and another one around Galactocentric radius R gal ∼ 5 kpc, followed by an exponential decrease as log(ΣSFR/[M⊙yr−1kpc−2])=aRgal/[kpc]+b , with a = −0.28 ± 0.01. In this regard, the fraction of SFR produced within and outside the solar circle is 84% and 16%, respectively; the fraction corresponding to the far outer Galaxy (R gal > 13.5 kpc) is only 1%. We also find that, for R gal > 3 kpc, our data follow a power law as a function of density, similarly to the Kennicutt–Schmidt relation. Finally, we compare the distribution of the SFR density across the face-on Galactic plane and those of median parameters, such as temperature, luminosity/mass ratio, and bolometric temperature, describing the evolutionary stage of Hi-GAL clumps. We found no clear correlation between the SFR and the clump evolutionary stage.

We present the stellar population properties of 69 short gamma-ray burst (GRB) host galaxies, representing the largest uniformly modeled sample to date. Using the Prospector stellar population inference code, we jointly fit photometry and/or spectroscopy of each host galaxy. We find a population median redshift of z=0.64−0.32+0.83 (68% confidence), including nine photometric redshifts at z ≳ 1. We further find a median mass-weighted age of t m = 0.8−0.53+2.71 Gyr, stellar mass of log(M */M ⊙) = 9.69−0.65+0.75 , star formation rate of SFR = 1.44−1.35+9.37 M ⊙ yr−1, stellar metallicity of log(Z */Z ⊙) = −0.38−0.42+0.44 , and dust attenuation of AV=0.43−0.36+0.85 mag (68% confidence). Overall, the majority of short GRB hosts are star-forming (≈84%), with small fractions that are either transitioning (≈6%) or quiescent (≈10%); however, we observe a much larger fraction (≈40%) of quiescent and transitioning hosts at z ≲ 0.25, commensurate with galaxy evolution. We find that short GRB hosts populate the star-forming main sequence of normal field galaxies, but do not include as many high-mass galaxies as the general galaxy population, implying that their binary neutron star (BNS) merger progenitors are dependent on a combination of host star formation and stellar mass. The distribution of ages and redshifts implies a broad delay-time distribution, with a fast-merging channel at z > 1 and a decreased neutron star binary formation efficiency from high to low redshifts. If short GRB hosts are representative of BNS merger hosts within the horizon of current gravitational wave detectors, these results can inform future searches for electromagnetic counterparts. All of the data and modeling products are available on the Broadband Repository for Investigating Gamma-ray burst Host Traits website.

We report the discovery of an accreting supermassive black hole at z = 8.679. This galaxy, denoted here as CEERS_1019, was previously discovered as a Lyα-break galaxy by Hubble with a Lyα redshift from Keck. As part of the Cosmic Evolution Early Release Science (CEERS) survey, we have observed this source with JWST/NIRSpec, MIRI, NIRCam, and NIRCam/WFSS and uncovered a plethora of emission lines. The Hβ line is best fit by a narrow plus a broad component, where the latter is measured at 2.5σ with an FWHM ∼1200 km s−1. We conclude this originates in the broadline region of an active galactic nucleus (AGN). This is supported by the presence of weak high-ionization lines (N V, N IV], and C III]), as well as a spatial point-source component. The implied mass of the black hole (BH) is log (M BH/M ⊙) = 6.95 ± 0.37, and we estimate that it is accreting at 1.2 ± 0.5 times the Eddington limit. The 1–8 μm photometric spectral energy distribution shows a continuum dominated by starlight and constrains the host galaxy to be massive (log M/M⊙ ∼9.5) and highly star-forming (star formation rate, or SFR ∼ 30 M⊙ yr−1; log sSFR ∼ − 7.9 yr−1). The line ratios show that the gas is metal-poor (Z/Z ⊙ ∼ 0.1), dense (n e ∼ 103 cm−3), and highly ionized (log U ∼ − 2.1). We use this present highest-redshift AGN discovery to place constraints on BH seeding models and find that a combination of either super-Eddington accretion from stellar seeds or Eddington accretion from very massive BH seeds is required to form this object.